## November 30, 2008

### How many do we need?

Guest question time. gammafunction sent in this question. Completely worded and framed by him. Thanks buddy!

This conjecture was first suggested by 1, in mid-19th century. The first public reference to it was in a paper by 2, who was a famous 19th century British Mathematician. After several attempts by a number of people, this was finally proved in the last quarter of the 20th century by these guys-3.Though all countries in the world conform to this theorem only 4. 5. and 6. do not.

Just give me the name of the theorem and the two men in 3.

and

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Answer:

Yes sir, we need 4 colors. The answer is the “Four color theorem”. Read the comments for more details.

Like shenoyvarun86 pointed out, we had asked this question in a different form. But we liked the way this question was framed, so it was posted.

the four colour theorem..

kenneth appel and wofgang haken..

1) Francis Guthrie

2) Arthur Cayley

3) The Four Color Theorem proved by Wolfgang Haken and Kenneth Appel…. which states that any map can be coloured with 4 colours with no two adjacent distinct region will recieve same colors….

4) USA

5) Azerbaijan

6) Russia

I am back… :)

Four Color Theorem – Kenneth Appel and Wolfgang Haken

1)Francis GUthrie

2) Cayley

3)The Appel-Haken duo

4)The 4 colour theorem

if I am not wrong this question had appeared on boiledbeans, in a different form, earlier.

The four colour theorem

The two men are Kenneth Appel and Wolfgang Haken

1. Francis Guthrie

2. Arthur Cayley

3. Kenneth Appel and Wolfgang Haken

Four Color Theorem

Guthrie, Cayley, Four Colour Theorem for maps, Kenneth Appel and Wolfgang Haken

Four Color Theorem by Francis Guthrie.

Proved by Kenneth Appel and Wolfgang Haken of University of Illinois

Four color theorem

Kenneth Appel and Wolfgang Haken

The four color theorem.

1) Francis Guthrie 2) Arthur Cayley 3)Kenneth Appel and Wolfgang Haken

U.S.A, Azerbaijan and Russia are non-contiguous countries.

The ‘Four Color’ theorem :-)

Is it the 4 colour theorem? that any map can be coloured by 4 distinct colours without two adjacent areas being coloured by the same colour…m guessing it from the cover of the book..as afaik the book is four colour suffice…

Four color theorem

Kenneth Appel & Wolfgang Haken

Four color theorem

Kenneth Appel and Wolfgang Haken

Four Color theorem

Four Colour Theorem, proved by Wolfgang Haken and Kenneth Appel

Four Color Theorem…

1. South African Mathematician – Francis Guthrie

2. British Mathematician – Arthur Cayley

3. Kenneth Appel & Wolfgang Haken from University of Illinois Urbana- Champaign solved the Four Color Theorem in 1976

Four color theorem solved by Wolfgang Haken & Kenneth Appel

four colour theorem

Four colour theorem

Kenneth Appel & Wolfgang Haken

Robin Wilson and Paul Erdős ,four colored theorem ??

2-> cayley

Ok, I stand corrected ..it’s Kenneth Appel and Wolfgang Haken

1->De Morgan

I stand corrected again.. :D 1 is Francis Guthrie

The four color theorem

(3) Wolfgang Haken and Kenneth Appel – the guys who proved it.

Nice question, btw.

four color theorem

francis guthrie

arthur cayley

haken-appel

Four Color Theorem

1. Francis Guthrie

2. Arthur Caley

3. Kenneth Appel and Wolfgang Haken

4,5 and 6. The U.S, Azerbaijan and Russia are three countries that the theorem does not apply to cause they aren\’t contiguous

Four color theorem

Benjamin Werner and Georges Gonthier

USA, Azerbaijan, Russia (and a few others…)

The Four colours theorem.

The two guys are Haken and Kenneth Appel.

We need 4. :)

The Four Colour Map Theorem. Solved by Kenneth Appel and Wolfgang Haken.

Four Color Theorem

3-Four color problem

4-Kenneth Appel and Wolfgang Haken

Four color theorem

1. Francis Guthrie

2. Arthur Cayley

3. Kenneth Appel and Wolfgang Haken

Four Color Theorem

Kenneth Appel and Wolfgang Haken

The four color theorem in graph theory that states that four colors are enough to color regions in a map without adjacent states being of the same color.

the guys who proved it are kenneth appel and wolfgang haken

the four colour map theorem

1. Francis Guthrie

2. Arthur Cayley

3. Kenneth appel & wolfgang haken (im guessing)

4 Color Theorem the first theotem to be proved using a software, Pic 2 has Kenneth Appel and Wolfgang Haken, the guys who proved it

Appel and Haken/ 4 colours.

Nice question!

Countries with non-contiguous regions may require more than 4 colours. The US, Azerbaijan and Russia aren\’t the only ones with non-contiguous regions. You just need to remove \

I think there is a problem with quotation marks in the comments.